Process of producing barium sulphate from barium sulphide



Patented Oct. 5, 1937 V t V UNITED STA ATENT OFFICE PROCESS OF PRGDUCINGBARIUM SUL- PHATE FROM BARIUM SULPHIDE Manfred Muller, Homberg, Germany,assignor to firm Sachtleben Aktiengesellschaft fiir Bergbau undChemische Industrie, Cologne-on-the- Rhine, Germany No Drawing.Application February 7, 1936, Se-

rial No. 62,813. In Germany February 25, 1935 i 1 Claim. (Cl. 23-122)The present invention relates to a process of barium sulphate andcarbonic acid after the producing barium-sulphate (permanent white)equation: from barium-sulphide.

Precipitated barium sulphate is usually pro- Bacos+H2SO4 B&SO4+H2O+CO2 5duced by causing a conversion between a water- The carbonic acid setfree is reintroduced into 5 soluble barium compound and sulphuric acidor the process and used to decompose fresh amounts sulphates. Thecheapest water-soluble barium of b um u p Whilst the barium Sulphatecompound which can be obtained from nat ral in known manner is subjectedto a further treatheavy spar, is the barium sulphide, and the ment,whereby Permanent White in the form of simplest way to obtainprecipitated barium sul- & p e 1 a p d s a d as end D 10 phate is todecompose barium sulphide with sul- Th described v l pr has vanta e ofphuric acid after the equation: various kinds. The permanent whiteobtained, shows a white color of extreme purity, because no BaS+H s0=Bas0 +H s hydrogen sulphide is present and therefore no dark heavymetal sulphides are formed. Such 15 This process does however give aproduct which sulphides always impart a greyish color to the preisgreyish and disagreeable looking, and it is c p tated barium Sulphate-In e ve D Ce therefore difficult to get the same sold. Morealso noby-products are formed which would over, the treatment of th hydrogensulphide need further treatment and for which, from formed by thedecomposition is very complicated conomical reasons, a market would haveto be 20 and causes much inconvenience, particularly bef und. cause thishydrogen sulphide is dissolved in the n e novel p ess, Which y bedefined as precipitated mass, It has also be proposed t an economicaloxidation of 325 to 33304, all inproduce barium sulphate by co v rtin thtermediate products enter at once again into re water-insoluble bariumcarbonate or witherite action after the equations! 25 with sulphuricacid. On account of the costs of the starting material this process ishowever not i economical. BaS-l- H2CO BaCO H S According to the presentinvention, the sul- H2S+2O2=H2S04 phide ion is oxidized to sulphate ionor sulphuric H2SO4+BaCO3=BaSO4+H2CO3 30 acid separate from the bariumion, and the con- Thus, the only Starting material is Bas and stituentsare thereupon combined to barium sulthe only end product is BaSOn phate.The BaS is indirectly oxidized to BaSO4. What I claim is: i i A directoxidation is from economical reasons not A continuous cyclic process ofproducing b r accomplishable. Barium sulphide is for instance um ulphatefrom b rium ulphide, comprising 5 in a mann r k w p Se y m s of carbonicthe steps of first converting the barium sulphide acid decomposed nto aum I'bO aUE and hyinto barium carbonate and hydrogen sulphide by r nsulphid after the equation: reacting said barium sulphide with gaseouscarbonic acid, thereupon oxidizing the hydrogen sul- 40BaS+H2CO3=BaCO3+H2S phide to sulphuric acid, converting the barium 40carbonate into barium sulphate and carbonic acid The y gen sulphide fore combusted by reacting same with sulphuric acid so produced wherebysulphurous acid is formed, and t s ac d and reintroducing the carbonicacid thus obis in known manner converted into sulp c tained into theprocess for the first conversion By means of the sulphuric acid obtainedin this of the barium sulphide. 45

manner the barium carbonate is decomposed into MANFRED MfiLLER.

